1 /*
2 * intel_pt.c: Intel Processor Trace support
3 * Copyright (c) 2013-2015, Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 */
15
16 #include <stdbool.h>
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/bitops.h>
20 #include <linux/log2.h>
21 #include <cpuid.h>
22
23 #include "../../perf.h"
24 #include "../../util/session.h"
25 #include "../../util/event.h"
26 #include "../../util/evlist.h"
27 #include "../../util/evsel.h"
28 #include "../../util/cpumap.h"
29 #include <subcmd/parse-options.h>
30 #include "../../util/parse-events.h"
31 #include "../../util/pmu.h"
32 #include "../../util/debug.h"
33 #include "../../util/auxtrace.h"
34 #include "../../util/tsc.h"
35 #include "../../util/intel-pt.h"
36
37 #define KiB(x) ((x) * 1024)
38 #define MiB(x) ((x) * 1024 * 1024)
39 #define KiB_MASK(x) (KiB(x) - 1)
40 #define MiB_MASK(x) (MiB(x) - 1)
41
42 #define INTEL_PT_DEFAULT_SAMPLE_SIZE KiB(4)
43
44 #define INTEL_PT_MAX_SAMPLE_SIZE KiB(60)
45
46 #define INTEL_PT_PSB_PERIOD_NEAR 256
47
48 struct intel_pt_snapshot_ref {
49 void *ref_buf;
50 size_t ref_offset;
51 bool wrapped;
52 };
53
54 struct intel_pt_recording {
55 struct auxtrace_record itr;
56 struct perf_pmu *intel_pt_pmu;
57 int have_sched_switch;
58 struct perf_evlist *evlist;
59 bool snapshot_mode;
60 bool snapshot_init_done;
61 size_t snapshot_size;
62 size_t snapshot_ref_buf_size;
63 int snapshot_ref_cnt;
64 struct intel_pt_snapshot_ref *snapshot_refs;
65 size_t priv_size;
66 };
67
intel_pt_parse_terms_with_default(struct list_head * formats,const char * str,u64 * config)68 static int intel_pt_parse_terms_with_default(struct list_head *formats,
69 const char *str,
70 u64 *config)
71 {
72 struct list_head *terms;
73 struct perf_event_attr attr = { .size = 0, };
74 int err;
75
76 terms = malloc(sizeof(struct list_head));
77 if (!terms)
78 return -ENOMEM;
79
80 INIT_LIST_HEAD(terms);
81
82 err = parse_events_terms(terms, str);
83 if (err)
84 goto out_free;
85
86 attr.config = *config;
87 err = perf_pmu__config_terms(formats, &attr, terms, true, NULL);
88 if (err)
89 goto out_free;
90
91 *config = attr.config;
92 out_free:
93 parse_events_terms__delete(terms);
94 return err;
95 }
96
intel_pt_parse_terms(struct list_head * formats,const char * str,u64 * config)97 static int intel_pt_parse_terms(struct list_head *formats, const char *str,
98 u64 *config)
99 {
100 *config = 0;
101 return intel_pt_parse_terms_with_default(formats, str, config);
102 }
103
intel_pt_masked_bits(u64 mask,u64 bits)104 static u64 intel_pt_masked_bits(u64 mask, u64 bits)
105 {
106 const u64 top_bit = 1ULL << 63;
107 u64 res = 0;
108 int i;
109
110 for (i = 0; i < 64; i++) {
111 if (mask & top_bit) {
112 res <<= 1;
113 if (bits & top_bit)
114 res |= 1;
115 }
116 mask <<= 1;
117 bits <<= 1;
118 }
119
120 return res;
121 }
122
intel_pt_read_config(struct perf_pmu * intel_pt_pmu,const char * str,struct perf_evlist * evlist,u64 * res)123 static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str,
124 struct perf_evlist *evlist, u64 *res)
125 {
126 struct perf_evsel *evsel;
127 u64 mask;
128
129 *res = 0;
130
131 mask = perf_pmu__format_bits(&intel_pt_pmu->format, str);
132 if (!mask)
133 return -EINVAL;
134
135 evlist__for_each_entry(evlist, evsel) {
136 if (evsel->attr.type == intel_pt_pmu->type) {
137 *res = intel_pt_masked_bits(mask, evsel->attr.config);
138 return 0;
139 }
140 }
141
142 return -EINVAL;
143 }
144
intel_pt_psb_period(struct perf_pmu * intel_pt_pmu,struct perf_evlist * evlist)145 static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu,
146 struct perf_evlist *evlist)
147 {
148 u64 val;
149 int err, topa_multiple_entries;
150 size_t psb_period;
151
152 if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries",
153 "%d", &topa_multiple_entries) != 1)
154 topa_multiple_entries = 0;
155
156 /*
157 * Use caps/topa_multiple_entries to indicate early hardware that had
158 * extra frequent PSBs.
159 */
160 if (!topa_multiple_entries) {
161 psb_period = 256;
162 goto out;
163 }
164
165 err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val);
166 if (err)
167 val = 0;
168
169 psb_period = 1 << (val + 11);
170 out:
171 pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
172 return psb_period;
173 }
174
intel_pt_pick_bit(int bits,int target)175 static int intel_pt_pick_bit(int bits, int target)
176 {
177 int pos, pick = -1;
178
179 for (pos = 0; bits; bits >>= 1, pos++) {
180 if (bits & 1) {
181 if (pos <= target || pick < 0)
182 pick = pos;
183 if (pos >= target)
184 break;
185 }
186 }
187
188 return pick;
189 }
190
intel_pt_default_config(struct perf_pmu * intel_pt_pmu)191 static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
192 {
193 char buf[256];
194 int mtc, mtc_periods = 0, mtc_period;
195 int psb_cyc, psb_periods, psb_period;
196 int pos = 0;
197 u64 config;
198
199 pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
200
201 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d",
202 &mtc) != 1)
203 mtc = 1;
204
205 if (mtc) {
206 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x",
207 &mtc_periods) != 1)
208 mtc_periods = 0;
209 if (mtc_periods) {
210 mtc_period = intel_pt_pick_bit(mtc_periods, 3);
211 pos += scnprintf(buf + pos, sizeof(buf) - pos,
212 ",mtc,mtc_period=%d", mtc_period);
213 }
214 }
215
216 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
217 &psb_cyc) != 1)
218 psb_cyc = 1;
219
220 if (psb_cyc && mtc_periods) {
221 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
222 &psb_periods) != 1)
223 psb_periods = 0;
224 if (psb_periods) {
225 psb_period = intel_pt_pick_bit(psb_periods, 3);
226 pos += scnprintf(buf + pos, sizeof(buf) - pos,
227 ",psb_period=%d", psb_period);
228 }
229 }
230
231 pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
232
233 intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
234
235 return config;
236 }
237
intel_pt_parse_snapshot_options(struct auxtrace_record * itr,struct record_opts * opts,const char * str)238 static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr,
239 struct record_opts *opts,
240 const char *str)
241 {
242 struct intel_pt_recording *ptr =
243 container_of(itr, struct intel_pt_recording, itr);
244 unsigned long long snapshot_size = 0;
245 char *endptr;
246
247 if (str) {
248 snapshot_size = strtoull(str, &endptr, 0);
249 if (*endptr || snapshot_size > SIZE_MAX)
250 return -1;
251 }
252
253 opts->auxtrace_snapshot_mode = true;
254 opts->auxtrace_snapshot_size = snapshot_size;
255
256 ptr->snapshot_size = snapshot_size;
257
258 return 0;
259 }
260
261 struct perf_event_attr *
intel_pt_pmu_default_config(struct perf_pmu * intel_pt_pmu)262 intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
263 {
264 struct perf_event_attr *attr;
265
266 attr = zalloc(sizeof(struct perf_event_attr));
267 if (!attr)
268 return NULL;
269
270 attr->config = intel_pt_default_config(intel_pt_pmu);
271
272 intel_pt_pmu->selectable = true;
273
274 return attr;
275 }
276
intel_pt_find_filter(struct perf_evlist * evlist,struct perf_pmu * intel_pt_pmu)277 static const char *intel_pt_find_filter(struct perf_evlist *evlist,
278 struct perf_pmu *intel_pt_pmu)
279 {
280 struct perf_evsel *evsel;
281
282 evlist__for_each_entry(evlist, evsel) {
283 if (evsel->attr.type == intel_pt_pmu->type)
284 return evsel->filter;
285 }
286
287 return NULL;
288 }
289
intel_pt_filter_bytes(const char * filter)290 static size_t intel_pt_filter_bytes(const char *filter)
291 {
292 size_t len = filter ? strlen(filter) : 0;
293
294 return len ? roundup(len + 1, 8) : 0;
295 }
296
297 static size_t
intel_pt_info_priv_size(struct auxtrace_record * itr,struct perf_evlist * evlist)298 intel_pt_info_priv_size(struct auxtrace_record *itr, struct perf_evlist *evlist)
299 {
300 struct intel_pt_recording *ptr =
301 container_of(itr, struct intel_pt_recording, itr);
302 const char *filter = intel_pt_find_filter(evlist, ptr->intel_pt_pmu);
303
304 ptr->priv_size = (INTEL_PT_AUXTRACE_PRIV_MAX * sizeof(u64)) +
305 intel_pt_filter_bytes(filter);
306
307 return ptr->priv_size;
308 }
309
intel_pt_tsc_ctc_ratio(u32 * n,u32 * d)310 static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d)
311 {
312 unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
313
314 __get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
315 *n = ebx;
316 *d = eax;
317 }
318
intel_pt_info_fill(struct auxtrace_record * itr,struct perf_session * session,struct auxtrace_info_event * auxtrace_info,size_t priv_size)319 static int intel_pt_info_fill(struct auxtrace_record *itr,
320 struct perf_session *session,
321 struct auxtrace_info_event *auxtrace_info,
322 size_t priv_size)
323 {
324 struct intel_pt_recording *ptr =
325 container_of(itr, struct intel_pt_recording, itr);
326 struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
327 struct perf_event_mmap_page *pc;
328 struct perf_tsc_conversion tc = { .time_mult = 0, };
329 bool cap_user_time_zero = false, per_cpu_mmaps;
330 u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
331 u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
332 unsigned long max_non_turbo_ratio;
333 size_t filter_str_len;
334 const char *filter;
335 u64 *info;
336 int err;
337
338 if (priv_size != ptr->priv_size)
339 return -EINVAL;
340
341 intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
342 intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
343 &noretcomp_bit);
344 intel_pt_parse_terms(&intel_pt_pmu->format, "mtc", &mtc_bit);
345 mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
346 "mtc_period");
347 intel_pt_parse_terms(&intel_pt_pmu->format, "cyc", &cyc_bit);
348
349 intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
350
351 if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio",
352 "%lu", &max_non_turbo_ratio) != 1)
353 max_non_turbo_ratio = 0;
354
355 filter = intel_pt_find_filter(session->evlist, ptr->intel_pt_pmu);
356 filter_str_len = filter ? strlen(filter) : 0;
357
358 if (!session->evlist->nr_mmaps)
359 return -EINVAL;
360
361 pc = session->evlist->mmap[0].base;
362 if (pc) {
363 err = perf_read_tsc_conversion(pc, &tc);
364 if (err) {
365 if (err != -EOPNOTSUPP)
366 return err;
367 } else {
368 cap_user_time_zero = tc.time_mult != 0;
369 }
370 if (!cap_user_time_zero)
371 ui__warning("Intel Processor Trace: TSC not available\n");
372 }
373
374 per_cpu_mmaps = !cpu_map__empty(session->evlist->cpus);
375
376 auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
377 auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
378 auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
379 auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
380 auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
381 auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
382 auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
383 auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
384 auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
385 auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
386 auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
387 auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit;
388 auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits;
389 auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
390 auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
391 auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
392 auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio;
393 auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] = filter_str_len;
394
395 info = &auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] + 1;
396
397 if (filter_str_len) {
398 size_t len = intel_pt_filter_bytes(filter);
399
400 strncpy((char *)info, filter, len);
401 info += len >> 3;
402 }
403
404 return 0;
405 }
406
intel_pt_track_switches(struct perf_evlist * evlist)407 static int intel_pt_track_switches(struct perf_evlist *evlist)
408 {
409 const char *sched_switch = "sched:sched_switch";
410 struct perf_evsel *evsel;
411 int err;
412
413 if (!perf_evlist__can_select_event(evlist, sched_switch))
414 return -EPERM;
415
416 err = parse_events(evlist, sched_switch, NULL);
417 if (err) {
418 pr_debug2("%s: failed to parse %s, error %d\n",
419 __func__, sched_switch, err);
420 return err;
421 }
422
423 evsel = perf_evlist__last(evlist);
424
425 perf_evsel__set_sample_bit(evsel, CPU);
426 perf_evsel__set_sample_bit(evsel, TIME);
427
428 evsel->system_wide = true;
429 evsel->no_aux_samples = true;
430 evsel->immediate = true;
431
432 return 0;
433 }
434
intel_pt_valid_str(char * str,size_t len,u64 valid)435 static void intel_pt_valid_str(char *str, size_t len, u64 valid)
436 {
437 unsigned int val, last = 0, state = 1;
438 int p = 0;
439
440 str[0] = '\0';
441
442 for (val = 0; val <= 64; val++, valid >>= 1) {
443 if (valid & 1) {
444 last = val;
445 switch (state) {
446 case 0:
447 p += scnprintf(str + p, len - p, ",");
448 /* Fall through */
449 case 1:
450 p += scnprintf(str + p, len - p, "%u", val);
451 state = 2;
452 break;
453 case 2:
454 state = 3;
455 break;
456 case 3:
457 state = 4;
458 break;
459 default:
460 break;
461 }
462 } else {
463 switch (state) {
464 case 3:
465 p += scnprintf(str + p, len - p, ",%u", last);
466 state = 0;
467 break;
468 case 4:
469 p += scnprintf(str + p, len - p, "-%u", last);
470 state = 0;
471 break;
472 default:
473 break;
474 }
475 if (state != 1)
476 state = 0;
477 }
478 }
479 }
480
intel_pt_val_config_term(struct perf_pmu * intel_pt_pmu,const char * caps,const char * name,const char * supported,u64 config)481 static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
482 const char *caps, const char *name,
483 const char *supported, u64 config)
484 {
485 char valid_str[256];
486 unsigned int shift;
487 unsigned long long valid;
488 u64 bits;
489 int ok;
490
491 if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
492 valid = 0;
493
494 if (supported &&
495 perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
496 valid = 0;
497
498 valid |= 1;
499
500 bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
501
502 config &= bits;
503
504 for (shift = 0; bits && !(bits & 1); shift++)
505 bits >>= 1;
506
507 config >>= shift;
508
509 if (config > 63)
510 goto out_err;
511
512 if (valid & (1 << config))
513 return 0;
514 out_err:
515 intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
516 pr_err("Invalid %s for %s. Valid values are: %s\n",
517 name, INTEL_PT_PMU_NAME, valid_str);
518 return -EINVAL;
519 }
520
intel_pt_validate_config(struct perf_pmu * intel_pt_pmu,struct perf_evsel * evsel)521 static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
522 struct perf_evsel *evsel)
523 {
524 int err;
525
526 if (!evsel)
527 return 0;
528
529 err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
530 "cyc_thresh", "caps/psb_cyc",
531 evsel->attr.config);
532 if (err)
533 return err;
534
535 err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
536 "mtc_period", "caps/mtc",
537 evsel->attr.config);
538 if (err)
539 return err;
540
541 return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
542 "psb_period", "caps/psb_cyc",
543 evsel->attr.config);
544 }
545
intel_pt_recording_options(struct auxtrace_record * itr,struct perf_evlist * evlist,struct record_opts * opts)546 static int intel_pt_recording_options(struct auxtrace_record *itr,
547 struct perf_evlist *evlist,
548 struct record_opts *opts)
549 {
550 struct intel_pt_recording *ptr =
551 container_of(itr, struct intel_pt_recording, itr);
552 struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
553 bool have_timing_info, need_immediate = false;
554 struct perf_evsel *evsel, *intel_pt_evsel = NULL;
555 const struct cpu_map *cpus = evlist->cpus;
556 bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
557 u64 tsc_bit;
558 int err;
559
560 ptr->evlist = evlist;
561 ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
562
563 evlist__for_each_entry(evlist, evsel) {
564 if (evsel->attr.type == intel_pt_pmu->type) {
565 if (intel_pt_evsel) {
566 pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
567 return -EINVAL;
568 }
569 evsel->attr.freq = 0;
570 evsel->attr.sample_period = 1;
571 intel_pt_evsel = evsel;
572 opts->full_auxtrace = true;
573 }
574 }
575
576 if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
577 pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
578 return -EINVAL;
579 }
580
581 if (opts->use_clockid) {
582 pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n");
583 return -EINVAL;
584 }
585
586 if (!opts->full_auxtrace)
587 return 0;
588
589 err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
590 if (err)
591 return err;
592
593 /* Set default sizes for snapshot mode */
594 if (opts->auxtrace_snapshot_mode) {
595 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
596
597 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
598 if (privileged) {
599 opts->auxtrace_mmap_pages = MiB(4) / page_size;
600 } else {
601 opts->auxtrace_mmap_pages = KiB(128) / page_size;
602 if (opts->mmap_pages == UINT_MAX)
603 opts->mmap_pages = KiB(256) / page_size;
604 }
605 } else if (!opts->auxtrace_mmap_pages && !privileged &&
606 opts->mmap_pages == UINT_MAX) {
607 opts->mmap_pages = KiB(256) / page_size;
608 }
609 if (!opts->auxtrace_snapshot_size)
610 opts->auxtrace_snapshot_size =
611 opts->auxtrace_mmap_pages * (size_t)page_size;
612 if (!opts->auxtrace_mmap_pages) {
613 size_t sz = opts->auxtrace_snapshot_size;
614
615 sz = round_up(sz, page_size) / page_size;
616 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
617 }
618 if (opts->auxtrace_snapshot_size >
619 opts->auxtrace_mmap_pages * (size_t)page_size) {
620 pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
621 opts->auxtrace_snapshot_size,
622 opts->auxtrace_mmap_pages * (size_t)page_size);
623 return -EINVAL;
624 }
625 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
626 pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
627 return -EINVAL;
628 }
629 pr_debug2("Intel PT snapshot size: %zu\n",
630 opts->auxtrace_snapshot_size);
631 if (psb_period &&
632 opts->auxtrace_snapshot_size <= psb_period +
633 INTEL_PT_PSB_PERIOD_NEAR)
634 ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
635 opts->auxtrace_snapshot_size, psb_period);
636 }
637
638 /* Set default sizes for full trace mode */
639 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
640 if (privileged) {
641 opts->auxtrace_mmap_pages = MiB(4) / page_size;
642 } else {
643 opts->auxtrace_mmap_pages = KiB(128) / page_size;
644 if (opts->mmap_pages == UINT_MAX)
645 opts->mmap_pages = KiB(256) / page_size;
646 }
647 }
648
649 /* Validate auxtrace_mmap_pages */
650 if (opts->auxtrace_mmap_pages) {
651 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
652 size_t min_sz;
653
654 if (opts->auxtrace_snapshot_mode)
655 min_sz = KiB(4);
656 else
657 min_sz = KiB(8);
658
659 if (sz < min_sz || !is_power_of_2(sz)) {
660 pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2\n",
661 min_sz / 1024);
662 return -EINVAL;
663 }
664 }
665
666 intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
667
668 if (opts->full_auxtrace && (intel_pt_evsel->attr.config & tsc_bit))
669 have_timing_info = true;
670 else
671 have_timing_info = false;
672
673 /*
674 * Per-cpu recording needs sched_switch events to distinguish different
675 * threads.
676 */
677 if (have_timing_info && !cpu_map__empty(cpus)) {
678 if (perf_can_record_switch_events()) {
679 bool cpu_wide = !target__none(&opts->target) &&
680 !target__has_task(&opts->target);
681
682 if (!cpu_wide && perf_can_record_cpu_wide()) {
683 struct perf_evsel *switch_evsel;
684
685 err = parse_events(evlist, "dummy:u", NULL);
686 if (err)
687 return err;
688
689 switch_evsel = perf_evlist__last(evlist);
690
691 switch_evsel->attr.freq = 0;
692 switch_evsel->attr.sample_period = 1;
693 switch_evsel->attr.context_switch = 1;
694
695 switch_evsel->system_wide = true;
696 switch_evsel->no_aux_samples = true;
697 switch_evsel->immediate = true;
698
699 perf_evsel__set_sample_bit(switch_evsel, TID);
700 perf_evsel__set_sample_bit(switch_evsel, TIME);
701 perf_evsel__set_sample_bit(switch_evsel, CPU);
702
703 opts->record_switch_events = false;
704 ptr->have_sched_switch = 3;
705 } else {
706 opts->record_switch_events = true;
707 need_immediate = true;
708 if (cpu_wide)
709 ptr->have_sched_switch = 3;
710 else
711 ptr->have_sched_switch = 2;
712 }
713 } else {
714 err = intel_pt_track_switches(evlist);
715 if (err == -EPERM)
716 pr_debug2("Unable to select sched:sched_switch\n");
717 else if (err)
718 return err;
719 else
720 ptr->have_sched_switch = 1;
721 }
722 }
723
724 if (intel_pt_evsel) {
725 /*
726 * To obtain the auxtrace buffer file descriptor, the auxtrace
727 * event must come first.
728 */
729 perf_evlist__to_front(evlist, intel_pt_evsel);
730 /*
731 * In the case of per-cpu mmaps, we need the CPU on the
732 * AUX event.
733 */
734 if (!cpu_map__empty(cpus))
735 perf_evsel__set_sample_bit(intel_pt_evsel, CPU);
736 }
737
738 /* Add dummy event to keep tracking */
739 if (opts->full_auxtrace) {
740 struct perf_evsel *tracking_evsel;
741
742 err = parse_events(evlist, "dummy:u", NULL);
743 if (err)
744 return err;
745
746 tracking_evsel = perf_evlist__last(evlist);
747
748 perf_evlist__set_tracking_event(evlist, tracking_evsel);
749
750 tracking_evsel->attr.freq = 0;
751 tracking_evsel->attr.sample_period = 1;
752
753 if (need_immediate)
754 tracking_evsel->immediate = true;
755
756 /* In per-cpu case, always need the time of mmap events etc */
757 if (!cpu_map__empty(cpus)) {
758 perf_evsel__set_sample_bit(tracking_evsel, TIME);
759 /* And the CPU for switch events */
760 perf_evsel__set_sample_bit(tracking_evsel, CPU);
761 }
762 }
763
764 /*
765 * Warn the user when we do not have enough information to decode i.e.
766 * per-cpu with no sched_switch (except workload-only).
767 */
768 if (!ptr->have_sched_switch && !cpu_map__empty(cpus) &&
769 !target__none(&opts->target))
770 ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
771
772 return 0;
773 }
774
intel_pt_snapshot_start(struct auxtrace_record * itr)775 static int intel_pt_snapshot_start(struct auxtrace_record *itr)
776 {
777 struct intel_pt_recording *ptr =
778 container_of(itr, struct intel_pt_recording, itr);
779 struct perf_evsel *evsel;
780
781 evlist__for_each_entry(ptr->evlist, evsel) {
782 if (evsel->attr.type == ptr->intel_pt_pmu->type)
783 return perf_evsel__disable(evsel);
784 }
785 return -EINVAL;
786 }
787
intel_pt_snapshot_finish(struct auxtrace_record * itr)788 static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
789 {
790 struct intel_pt_recording *ptr =
791 container_of(itr, struct intel_pt_recording, itr);
792 struct perf_evsel *evsel;
793
794 evlist__for_each_entry(ptr->evlist, evsel) {
795 if (evsel->attr.type == ptr->intel_pt_pmu->type)
796 return perf_evsel__enable(evsel);
797 }
798 return -EINVAL;
799 }
800
intel_pt_alloc_snapshot_refs(struct intel_pt_recording * ptr,int idx)801 static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
802 {
803 const size_t sz = sizeof(struct intel_pt_snapshot_ref);
804 int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
805 struct intel_pt_snapshot_ref *refs;
806
807 if (!new_cnt)
808 new_cnt = 16;
809
810 while (new_cnt <= idx)
811 new_cnt *= 2;
812
813 refs = calloc(new_cnt, sz);
814 if (!refs)
815 return -ENOMEM;
816
817 memcpy(refs, ptr->snapshot_refs, cnt * sz);
818
819 ptr->snapshot_refs = refs;
820 ptr->snapshot_ref_cnt = new_cnt;
821
822 return 0;
823 }
824
intel_pt_free_snapshot_refs(struct intel_pt_recording * ptr)825 static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
826 {
827 int i;
828
829 for (i = 0; i < ptr->snapshot_ref_cnt; i++)
830 zfree(&ptr->snapshot_refs[i].ref_buf);
831 zfree(&ptr->snapshot_refs);
832 }
833
intel_pt_recording_free(struct auxtrace_record * itr)834 static void intel_pt_recording_free(struct auxtrace_record *itr)
835 {
836 struct intel_pt_recording *ptr =
837 container_of(itr, struct intel_pt_recording, itr);
838
839 intel_pt_free_snapshot_refs(ptr);
840 free(ptr);
841 }
842
intel_pt_alloc_snapshot_ref(struct intel_pt_recording * ptr,int idx,size_t snapshot_buf_size)843 static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
844 size_t snapshot_buf_size)
845 {
846 size_t ref_buf_size = ptr->snapshot_ref_buf_size;
847 void *ref_buf;
848
849 ref_buf = zalloc(ref_buf_size);
850 if (!ref_buf)
851 return -ENOMEM;
852
853 ptr->snapshot_refs[idx].ref_buf = ref_buf;
854 ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
855
856 return 0;
857 }
858
intel_pt_snapshot_ref_buf_size(struct intel_pt_recording * ptr,size_t snapshot_buf_size)859 static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
860 size_t snapshot_buf_size)
861 {
862 const size_t max_size = 256 * 1024;
863 size_t buf_size = 0, psb_period;
864
865 if (ptr->snapshot_size <= 64 * 1024)
866 return 0;
867
868 psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
869 if (psb_period)
870 buf_size = psb_period * 2;
871
872 if (!buf_size || buf_size > max_size)
873 buf_size = max_size;
874
875 if (buf_size >= snapshot_buf_size)
876 return 0;
877
878 if (buf_size >= ptr->snapshot_size / 2)
879 return 0;
880
881 return buf_size;
882 }
883
intel_pt_snapshot_init(struct intel_pt_recording * ptr,size_t snapshot_buf_size)884 static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
885 size_t snapshot_buf_size)
886 {
887 if (ptr->snapshot_init_done)
888 return 0;
889
890 ptr->snapshot_init_done = true;
891
892 ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
893 snapshot_buf_size);
894
895 return 0;
896 }
897
898 /**
899 * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
900 * @buf1: first buffer
901 * @compare_size: number of bytes to compare
902 * @buf2: second buffer (a circular buffer)
903 * @offs2: offset in second buffer
904 * @buf2_size: size of second buffer
905 *
906 * The comparison allows for the possibility that the bytes to compare in the
907 * circular buffer are not contiguous. It is assumed that @compare_size <=
908 * @buf2_size. This function returns %false if the bytes are identical, %true
909 * otherwise.
910 */
intel_pt_compare_buffers(void * buf1,size_t compare_size,void * buf2,size_t offs2,size_t buf2_size)911 static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
912 void *buf2, size_t offs2, size_t buf2_size)
913 {
914 size_t end2 = offs2 + compare_size, part_size;
915
916 if (end2 <= buf2_size)
917 return memcmp(buf1, buf2 + offs2, compare_size);
918
919 part_size = end2 - buf2_size;
920 if (memcmp(buf1, buf2 + offs2, part_size))
921 return true;
922
923 compare_size -= part_size;
924
925 return memcmp(buf1 + part_size, buf2, compare_size);
926 }
927
intel_pt_compare_ref(void * ref_buf,size_t ref_offset,size_t ref_size,size_t buf_size,void * data,size_t head)928 static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
929 size_t ref_size, size_t buf_size,
930 void *data, size_t head)
931 {
932 size_t ref_end = ref_offset + ref_size;
933
934 if (ref_end > buf_size) {
935 if (head > ref_offset || head < ref_end - buf_size)
936 return true;
937 } else if (head > ref_offset && head < ref_end) {
938 return true;
939 }
940
941 return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
942 buf_size);
943 }
944
intel_pt_copy_ref(void * ref_buf,size_t ref_size,size_t buf_size,void * data,size_t head)945 static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
946 void *data, size_t head)
947 {
948 if (head >= ref_size) {
949 memcpy(ref_buf, data + head - ref_size, ref_size);
950 } else {
951 memcpy(ref_buf, data, head);
952 ref_size -= head;
953 memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
954 }
955 }
956
intel_pt_wrapped(struct intel_pt_recording * ptr,int idx,struct auxtrace_mmap * mm,unsigned char * data,u64 head)957 static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
958 struct auxtrace_mmap *mm, unsigned char *data,
959 u64 head)
960 {
961 struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
962 bool wrapped;
963
964 wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
965 ptr->snapshot_ref_buf_size, mm->len,
966 data, head);
967
968 intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
969 data, head);
970
971 return wrapped;
972 }
973
intel_pt_first_wrap(u64 * data,size_t buf_size)974 static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
975 {
976 int i, a, b;
977
978 b = buf_size >> 3;
979 a = b - 512;
980 if (a < 0)
981 a = 0;
982
983 for (i = a; i < b; i++) {
984 if (data[i])
985 return true;
986 }
987
988 return false;
989 }
990
intel_pt_find_snapshot(struct auxtrace_record * itr,int idx,struct auxtrace_mmap * mm,unsigned char * data,u64 * head,u64 * old)991 static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx,
992 struct auxtrace_mmap *mm, unsigned char *data,
993 u64 *head, u64 *old)
994 {
995 struct intel_pt_recording *ptr =
996 container_of(itr, struct intel_pt_recording, itr);
997 bool wrapped;
998 int err;
999
1000 pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
1001 __func__, idx, (size_t)*old, (size_t)*head);
1002
1003 err = intel_pt_snapshot_init(ptr, mm->len);
1004 if (err)
1005 goto out_err;
1006
1007 if (idx >= ptr->snapshot_ref_cnt) {
1008 err = intel_pt_alloc_snapshot_refs(ptr, idx);
1009 if (err)
1010 goto out_err;
1011 }
1012
1013 if (ptr->snapshot_ref_buf_size) {
1014 if (!ptr->snapshot_refs[idx].ref_buf) {
1015 err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
1016 if (err)
1017 goto out_err;
1018 }
1019 wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
1020 } else {
1021 wrapped = ptr->snapshot_refs[idx].wrapped;
1022 if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
1023 ptr->snapshot_refs[idx].wrapped = true;
1024 wrapped = true;
1025 }
1026 }
1027
1028 /*
1029 * In full trace mode 'head' continually increases. However in snapshot
1030 * mode 'head' is an offset within the buffer. Here 'old' and 'head'
1031 * are adjusted to match the full trace case which expects that 'old' is
1032 * always less than 'head'.
1033 */
1034 if (wrapped) {
1035 *old = *head;
1036 *head += mm->len;
1037 } else {
1038 if (mm->mask)
1039 *old &= mm->mask;
1040 else
1041 *old %= mm->len;
1042 if (*old > *head)
1043 *head += mm->len;
1044 }
1045
1046 pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
1047 __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
1048
1049 return 0;
1050
1051 out_err:
1052 pr_err("%s: failed, error %d\n", __func__, err);
1053 return err;
1054 }
1055
intel_pt_reference(struct auxtrace_record * itr __maybe_unused)1056 static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
1057 {
1058 return rdtsc();
1059 }
1060
intel_pt_read_finish(struct auxtrace_record * itr,int idx)1061 static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
1062 {
1063 struct intel_pt_recording *ptr =
1064 container_of(itr, struct intel_pt_recording, itr);
1065 struct perf_evsel *evsel;
1066
1067 evlist__for_each_entry(ptr->evlist, evsel) {
1068 if (evsel->attr.type == ptr->intel_pt_pmu->type)
1069 return perf_evlist__enable_event_idx(ptr->evlist, evsel,
1070 idx);
1071 }
1072 return -EINVAL;
1073 }
1074
intel_pt_recording_init(int * err)1075 struct auxtrace_record *intel_pt_recording_init(int *err)
1076 {
1077 struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
1078 struct intel_pt_recording *ptr;
1079
1080 if (!intel_pt_pmu)
1081 return NULL;
1082
1083 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
1084 *err = -errno;
1085 return NULL;
1086 }
1087
1088 ptr = zalloc(sizeof(struct intel_pt_recording));
1089 if (!ptr) {
1090 *err = -ENOMEM;
1091 return NULL;
1092 }
1093
1094 ptr->intel_pt_pmu = intel_pt_pmu;
1095 ptr->itr.recording_options = intel_pt_recording_options;
1096 ptr->itr.info_priv_size = intel_pt_info_priv_size;
1097 ptr->itr.info_fill = intel_pt_info_fill;
1098 ptr->itr.free = intel_pt_recording_free;
1099 ptr->itr.snapshot_start = intel_pt_snapshot_start;
1100 ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
1101 ptr->itr.find_snapshot = intel_pt_find_snapshot;
1102 ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
1103 ptr->itr.reference = intel_pt_reference;
1104 ptr->itr.read_finish = intel_pt_read_finish;
1105 return &ptr->itr;
1106 }
1107